The present invention relates to an airbelt apparatus and an airbelt thereof for protecting an occupant of a moving object such as a vehicle upon a collision, and more specifically relates to an airbelt and an airbelt apparatus, in which an internal bag is inflated by gas from a gas generator.
Such an airbelt apparatus is disclosed in Japanese Unexamined Patent Application Publication No. 5-85301. FIG. 6 is a perspective view of an airbelt apparatus according to the Publication.
As shown in FIG. 1, the airbelt apparatus 1 includes an airbelt 2 diagonally extending from the right of an occupant to the left, a webbing 2a with one end connected to the airbelt 2, a lap belt 3 extending from the right of the occupant to the left, a buckle device 4 disposed on the floor of a vehicle body, etc., a tongue 5 to be inserted into and engaged with the buckle device 4 when the belt is fitted, and a through-anchor 6 for guiding the webbing 2a. 
The webbing 2a comprises a normal belt similar to a conventional and general seatbelt. The webbing 2a is slidably guided and hung-through by the through-anchor 6. The other end of the webbing 2a is connected to an emergency-locking-seatbelt retractor (ELR) 7 that is capable of winding up the webbing.
The upper end of the airbelt 2 is connected to the webbing 2a by sewing, etc., and the lower end of the airbelt is connected to the tongue 5 for connection to the buckle device 4.
The lap belt 3 is formed of a normal belt similar to a general seatbelt. One end of the lap belt 3 is connected to the tongue 5, while the other end is connected to a seatbelt retractor (ELR) 8 fixed to the vehicle body. A gas generator 9 is connected to the buckle device 4 for generating high-pressure gas when required in an emergency situation such as a vehicle collision.
The tongue 5 and the buckle device 4 are provided with a path for introducing gas from the gas generator 9 to the airbelt 2.
The airbelt 2 is a large-width belt-like bag, which is folded into a small-width belt-shape and is covered with a cover. The airbelt 2 retains its belt-shape under normal conditions. The airbelt apparatus 1 is used in a manner similar to that of a general seatbelt. When the gas generator 9 is operated upon a vehicle collision, etc., the airbelt 2 is inflated, as is shown in FIG. 6 by the dashed lines, so as to protect the occupant.
In the conventional airbelt apparatus described above, the separate webbing 2a is required to be connected to the airbelt 2 and wound around the retractor 7, because the thickness of the airbelt 2 is larger than that of the webbing 2a. As a result, the airbelt 2 is difficult to be passed through the through-anchor 6 and also difficult to be wound around the retractor 7.
It is therefore an object of the present invention to pass a belt, which is consecutively integrated with an inflating section of an airbelt, through a through-anchor and to wind the belt directly around a retractor, while omitting a separate webbing such as, for example, webbing 2a shown in FIG. 6.
According to the present invention an airbelt is provided. The airbelt comprises a belt, of which one half side of the longitudinal direction is a hollow and inflatable inflating section and the other half side is a non-inflating section. The airbelt further includes a bag placed within the inflating section of the belt, wherein the airbelt is inflated by introduction of gas into the bag. The belt may be consecutively and integrally made of a knitted fabric extending from the inflating section toward the non-inflating section. The airbelt also includes a weft thread comprising a fusion thread that is inserted into the non-inflating section.
Due to the weft thread being inserted into the non-inflating section of such an airbelt, when the non-inflating section is wound around the retractor, the airbelt cannot expand in the width direction. As a result the airbelt may be very smoothly wound around the retractor. Because the weft thread includes the fusion thread, by processing with heat, the non-inflating section has pliant rigidity while having extremely high strength.
The weft thread may be made of only the fusion thread or may be formed to include both the fusion thread and a non-fusion thread. When the weft thread is made of only the fusion thread, the knitting is simple. When the weft thread is lined up with the fusion thread and the non-fusion thread, the non-inflating section has extremely high strength.
In a preferred embodiment, the fusion thread comprises a thread having core-sheath structure including a core made of a regular polyester thread and a sheath made of thermo-fusion polyester. In the thread of the core-sheath structure, the core exhibits sufficient strength while the sheath exhibits sufficient fusion strength.
According to the present invention an airbelt apparatus may also be provided. The apparatus includes an airbelt to be inflatable by a gas generator, and may be mounted on a vehicle such as an automobile together with a tongue connected to one end of the airbelt and a retractor for winding the other end side of the airbelt.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed.